Stable regenerative bi-directional cell for bridge power inverters

ABSTRACT

A high efficiency, multi-mode, regenerative AC-DC-AC inverter power system contains an inverter bridge, a bi-phase matrix (BP-Mtx) containing reverse current oriented, series-connected sets of controllable switches, wherein inputs to a first and second set of controllable switches are coupled to the inputs of the first inverter bridge, and outputs of the first and second set of controllable switches are coupled to inputs to a third set of controllable switches. A chargeable DC power supply is coupled to an output of the third set of controllable switches. The load-side DC-bus is coupled to outputs of the first inverter bridge and a second inverter bridge. The switches of the first inverter bridge, second inverter bridge, and BP-Mtx are modulated to charge the DC power supply from either excess voltage from line inputs or the DC-bus, and to provide compensating energy from the DC power supply for load or line input perturbations.

BACKGROUND

1. Field

This invention relates to efficient recovery of energy in an AC-to-ACpower inverter system. More particularly, it relates to an efficientbi-directional circuit configuration with load stability for a powersource inverter system.

2. Background

It is common, for more sophisticated power systems that use three (3)phase AC line inputs, to implement a set of six (6) input switchingbidirectional inverters that flatten the input AC to a DC value. The DCis supplied to a bus that is coupled to six (6) output switchinginverters which then convert the DC back to AC. This AC-to-DC and fromDC-to-AC path provides needed output voltage stability and inputisolation, particularly when the input source is a “fluctuating” AC gridor if the load requires very stable power.

More advanced systems allow for power to be transferred back into theinput AC grid when the DC-bus voltage exceeds the normal input linevoltage, via the input bidirectional inverters. Due to all the switchingand circuit losses, the normal efficiency of these systems is around thelow 90%. In addition to these losses, these systems require a very largeDC-link capacitance bank to compensate for step-wise load variations(e.g., switching on an electric motor) that would otherwise causeunacceptable voltage/current fluctuations.

In view of the above, there has been a long-stand need in the industryfor inverter systems that have higher efficiencies and are lesssensitive to step loads. Solutions to these and other shortcomings inthe power inverter industry are elucidated in the following description.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the claimed subject matter. Thissummary is not an extensive overview, and is not intended to identifykey/critical elements or to delineate the scope of the claimed subjectmatter. Its purpose is to present some concepts in a simplified form asa prelude to the more detailed description that is presented later.

In one aspect of the disclosed embodiments, a multi-mode, regenerativeAC-DC-AC inverter power system is provided, comprising: a first inverterbridge with controllable switches configurable for coupling to lineinputs from a 3-phase AC power source; a bi-phase matrix (BP-Mtx)containing reverse current oriented, series-connected sets ofcontrollable BP-Mtx switches, wherein inputs to a first and second setof controllable BP-Mtx switches are coupled to the inputs of the firstinverter bridge, and outputs of the first and second set of controllableBP-Mtx switches are coupled to inputs to a third set of controllable BPswitches; a chargeable DC power supply coupled to an output of the thirdset of controllable BP-Mtx switches; a DC-bus coupled to outputs of thefirst inverter bridge; and a second inverter bridge with controllableswitches, inputs thereof coupled to an opposite end of the DC-bus fromthe first inverter bridge, and outputs thereof configurable for couplingto a load, wherein switches of at least the first inverter bridge,second inverter bridge, and BP-Mtx are controllable to charge the DCpower supply from at least one of excess voltage from the line inputsand DC-bus, and to provide compensating energy from the DC power supplyfor load or line input perturbations.

In other aspects of the above embodiment, the DC bus is shunted by atleast a DC voltage stabilizing capacitor; and/or the DC power supplycomprises at least one of a battery, an ultracapacitor, and disconnectswitch; and/or further comprises a switch controller, controllingswitches of at least the first inverter bridge, second inverter bridge,and BP-Mtx; and/or the switch controller utilizes a State Vector Method(SVM) for switch modulation; and/or switches of at least the firstinverter bridge, second inverter bridge, and BP-Mtx are at least one ofdiode bridged, field-effect transistors (FETs), powermetal-oxide-semiconductor-effect transistors (MOSFETs), andinsulated-gate-bipolar Transistors (IGBT); and/or the first inverterbridge and second inverter bridge are of a similar arrangement of sixdiode-bridged transistors in forward current oriented pairs connected inparallel, and the BP-Mtx switches are six diode-bridged transistors inan arrangement of non-parallel-connected upper switch pair, lower switchpair, and middle switch pair, wherein a first input of the middle switchpair is coupled to an output of the upper switch pair and a second inputof the middle switch pair is coupled to an output of the lower switchpair; and/or further comprises line inputs from a 3-phase AC powersource coupled to the first inverter bridge; and a load coupled to thesecond inverter bridge; and/or a DC boost circuit is coupled to the DCpower supply.

In another aspect of the disclosed embodiments, a multi-mode,regenerative AC-DC-AC inverter power system is provided, comprising: arectifying bridge configurable for coupling to line inputs from a first3-phase AC power source; a bi-phase matrix (BP-Mtx) comprising, reversecurrent oriented, series-connected sets of controllable BP-Mtx switches,wherein inputs to a first and second set of controllable BP-Mtx switchesare coupled to inputs of the rectifying bridge, and outputs of the firstand second set of controllable BP-Mtx switches are coupled to inputs toa third set of controllable BP-Mtx switches; a chargeable DC powersupply coupled to an output of the third set of controllable BP-Mtxswitches; a bridge connection coupled to outputs of the rectifyingbridge and to a DC-bus configurable for coupling to a load; and aninverter bridge with controllable switches, configurable for coupling toline inputs from a second 3-phase AC power source, wherein an output ofthe inverter bridge is coupled to at least one of the bridge connectionand the DC-bus, wherein switches of at least the BP-Mtx and inverterbridge are controllable to charge the DC power supply from at least oneof excess voltage from the line inputs and DC-bus, and to providecompensating energy from the DC power supply for load or line inputperturbations.

In other aspects of the above embodiment, the DC-bus is shunted by atleast a DC voltage stabilizing capacitor; and/or the DC power supplycomprises at least one of a battery, an ultracapacitor, and disconnectswitch; and/or a switch controller controls switches of at least theBP-Mtx and inverter bridge; and/or the switch controller utilizes aState Vector Method (SVM) for switch modulation; and/or a DC boostcircuit coupled to the DC power supply; and/or switches of at least theBP-Mtx and inverter bridge are at least one of diode bridged,field-effect transistors (FETs), power metal-oxide-semiconductor-effecttransistors (MOSFETs), and insulated-gate-bipolar Transistors (IGBT);and/or the BP-Mtx switches are six diode-bridged transistors in anarrangement of non-parallel-connected upper switch pair, lower switchpair, and middle switch pair, wherein a first input of the middle switchpair is coupled to an output of the upper switch pair and a second inputof the middle switch pair is coupled to an output of the lower switchpair.

In another aspect of the disclosed embodiments, a method of operating amulti-mode, regenerative AC-DC-AC inverter power system is provided,comprising: a computerized system controller detecting a bus instabilityevent in a multi-mode, regenerative AC-DC-AC inverter power system, andupon detection; automatically determining if a de power source coupledto the system is available for power regeneration and if so,automatically activating a regeneration mode and applying voltage fromthe dc power source to the system; wherein if the dc power source is notavailable for power regeneration, automatically determining if the dcpower source has a low voltage and if so, automatically charging the dcpower source from available power, wherein if the dc power source doesnot have low voltage, automatically determining if the dc power sourceis charging and if so, automatically charging the dc power source fromavailable power, wherein if the dc power source is not charging toautomatically activate the regeneration mode and apply voltage from thedc power source to the system.

In other aspects of the above embodiment, wherein after completion of atleast one of the steps of applying voltage from the dc power source tothe system and charging the dc power source from available power,automatically returning to detecting a bus instability event; and/orwherein, upon activating a regeneration mode, determining, by thecontroller, if a voltage of a dc bus of the system has a voltage greaterthan a voltage of an AC grid input and if so, proceeding to the step ofautomatically determining if the dc power source is charging, wherein ifthe voltage of the dc bus is less than the voltage of the AC grid input,returning to a regeneration mode monitoring mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a related art AC-DC-AC inverter system.

FIG. 2 is a schematic of a related art AC-DC-AC inverter system withbidirectional inverter switches.

FIG. 3 is a schematic of an inverter system modified with a bi-phasematrix switch operation and DC-energy source for increased efficiency.

FIG. 4 is a schematic of the embodiment of FIG. 3 modified with a DCboost circuit.

FIG. 5 is a schematic of the embodiment of FIG. 4 with two 3-phase linesources.

FIG. 6 is a block diagram of a modified inverted system under controlleroperation.

FIG. 7 is process flow chart for event-based actions for a modifiedinverted system under controller operation.

FIG. 8 is a plot of a computer simulation of the related art embodimentof FIG. 1.

FIG. 9 is a plot of a computer simulation of the embodiment of FIG. 4without boost.

FIG. 10 is a plot of a computer simulation of the embodiment of FIG. 4with boost.

FIG. 11 is a plot of a computer simulation of the embodiment of FIG. 4without DC power source contribution.

FIG. 12 is a plot of a computer simulation of the embodiment of FIG. 5without a common link between rectifier systems.

FIG. 13 is a plot of a computer simulation of the embodiment of FIG. 5with a common link between rectifier systems.

FIG. 14 is a plot of a computer simulation of the embodiment of FIG. 5with a common link between rectifier systems and boosting.

FIG. 15A is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with a single input,single output.

FIG. 15B is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with dual input,bridging and single output.

FIG. 15C is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with a single input, aDC power supply, and single output.

FIG. 15D is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with dual input,bridging and dual outputs.

FIG. 15E is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with dual input,bridging, DC power supply and single output.

FIG. 15F is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system with dual input,bridging, DC power supply, and dual outputs.

DETAILED DESCRIPTION

Various embodiments described below allow for an AC-to-DC-to-AC powerinverter architecture to operate with higher efficiency and alsorecharge/supply a supplemental DC source. Various embodiments alsoprovide superior step load stability and configurability for multiplesource/load scenarios, as well as other capabilities as described in thefollowing figures.

FIG. 1 is a schematic diagram 100 of a related art AC-DC-AC invertersystem being fed by an AC grid 110 to rectifying input switches 120,coupled to alternating output switches 130 and finally to a load 140.The AC grid 110 is shown here as being three single phase line inputswith arbitrary line resistances 112 and inductors 114. The inputswitches 120 are the typical transistor-diode switch 122, controlled bya switching system (not shown). The input switches 120 are arranged in aspecific pattern to synchronously rectify the AC grid 110 voltage tocreate a DC voltage between Bus V+ (153) and Bus V− (155), beingstabilized by capacitor 150. For ease of description, the Bus voltagepoints 153, 155 will hereafter be referred to as the DC-bus 160 orDC-link.

The DC-bus 160 supplies a “stable” DC voltage to a secondary set of“de-rectifying” switches 130, also having the typical transistor-diode132 configuration, which are controlled by a switching system (notshown) to result in an AC output. The now regulated and controlled ACoutput is fed to the load 140, shown here, for example, as a motor.Aspects of this related-art architecture are well known and understoodin the art and therefore, further elaboration is not provided.

FIG. 2 is a schematic diagram 200 of another related art AC-DC-ACinverter system being fed by an AC grid 110 to rectifying input switches120 in conjunction with bidirectional switches 180, to supply a DCvoltage to DC-bus 160, which feeds alternating output switches 130supplying a regulated AC voltage to load 140. The AC grid 110 is shownin this FIG. with shunting resistors 127 and capacitors 129 added forcompleteness of the equivalent circuit. Similarly, DC-bus 160, with BusV+ (153), Bus V− (155) and capacitor 150 is complemented with seriesline resistance 156 and shunt resistance 158, for completeness of theequivalent circuit.

Other than the added circuit elements, the primary difference in thisarchitecture versus the architecture of FIG. 1 is the addition of thebank of bidirectional switches 180 which are set up in diode-reversedpairs. These switches 180 are typically FETD switches controlled by asystem controller (not shown) to allow a balancing of the voltages atthe input of rectifying input switches 120. These switches are normallyoperated with a higher pulse width modulation (PWM) switching frequencythan would normally be associated with a conventional rectifier input,resulting in nominally increased efficiency (approximately 95%) andlower Total Harmonic Distortion (THD). The embodiment of FIG. 2represents the current state-of-the art. Aspects of this related-artarchitecture are well known and understood in the art and therefore,further elaboration is not provided.

The following FIGS. illustrate aspects of various embodiments of animproved inverter architecture where a rectifying switch arrangement isadded to provide power to the DC link. This “double” rectifyingarchitecture operates to enhance power quality, efficiency, andregenerative capability. A specialized switch arrangement is used thatoperates to rectify and also permits controlled, bi-directional flow ofcurrent/voltage. To differentiate this operational mode/arrangement ofswitches from other switch arrangements, the term “bi-phase” matrix willhereafter be used. The improved architecture also contemplates aseparate added DC power source to allow for regeneration from the DCpower source. Other aspects and variations of the improved inverterarchitecture are detailed below.

FIG. 3 is a schematic diagram 300 of an embodiment of a modifiedinverter architecture with a rectifying switch configuration 310(bi-phase matrix) connected to the input of the rectifying inputswitches 120. A DC source circuit 360, representing one or moreindependent (or dependent) power supplies 362 such as, for example, abattery, solar cell, etc. is coupled to the midpoint of the bi-phasematrix 310, allowing, in some instances, adjunct DC current to besupplied to the rectifying input switches 120 or, alternatively, amechanism for storing energy arising from the modified inverterarchitecture. An optional disconnect switch 369 is provided to allow foropening/closing a path to power supply 362, for possible safety reasonsand also to allow operation of the bi-phase matrix 310 independent fromthe DC source circuit 360/power supply 362.

For completeness of circuit equivalence, particularly in the context ofrunning a circuit simulation, the DC source circuit 360 is illustratedhere as having a series resistance 364 with a shunt resistance 366, andshunt capacitance 368. Similarly, the AC grid 110 is shown with shuntresistance 325 and shunt capacitance 325. These resistances,capacitances (and also inductances, if applicable) may be, in someembodiments, considered intrinsic circuit equivalences, which may beconsidered negligible and ignored, depending on the sophistication ofsimulation being performed. Accordingly, depending on the “accuracy”desired, these intrinsic equivalences may be removed and the modifiedinverter architecture may suitably operate.

The output of the rectifying input switches 120 is fed to DC-bus 350,having series and shunt resistors 356 and 348, respectively, and buscapacitor 355 to float a “stable” DC voltage to a set of controlledoutput alternating switches 330, having a transistor-diode 332configuration, for AC output. The now regulated and controlled AC outputis fed to the load 140, shown here, for example, as a motor. Of course,other load types and circuits interleaved between the load and theoutput alternating switches 330 may be connected, according toapplication preference.

While rectifying input switches 120 and output alternating switches 330may be a simple transistor-diode arrangement, other types of transistorsor switching devices that are suitable may be used, according to designpreference. For example, in some embodiments, FET (aka—field effecttransistors) or insulated gate bipolar transistors (IGBTs) or powerMOSFETs, and so forth, may be used. Similarly, the switches of thebi-phase matrix 310 may be of a different type of switching circuit thanshown in FIG. 3. The bi-phase matrix 310 operates as a balanced input,controllably bi-directional switching system, regulating current fedinto or drawn from the DC source circuit 360.

In operation, input line A's voltage from AC grid 110 three single phaseline sources (in 3-phase rotation) will encounter rectifying inputswitch 121, having transistor 121 a paired to diode 121 b. If input lineA's voltage is positive, then diode 121 b will be forward biased andforward the voltage to DC-bus 350, presuming the transistors ofrectifying input switches 123, 125 are turned “off.” For the negativephase of input line A's voltage, rectifying input switch 122 willprovide the negative voltage path to DC-bus 350. As input lines B, C ofAC grid 110 phase follow input line A, they similarly are forwarded asthey alternate between positive and negative values via their respective+/− paired rectifying input switches (123, 124 and 125, 126). By turningon the transistors at specific points of the input phases, simplerectification is converted to inverter operation.

While input line A's voltage is fed to the rectifying input switches120, it is also input to bi-phase matrix 310 via switch 312 whose diodeis back-biased, preventing default entry to the bi-phase matrix 310.Switch 312 is also connected to input line C of AC grid 110 through thepath of lower switch pairs 315, 316, and since the diode of switch 315is back-biased, default entry of input line C voltage into the bi-phasematrix 310 is prevented. Line B of AC grid 110 is also connected to thebi-phase matrix 310 via switch 311, also being back-biased, preventingdefault entry of input line B into the bi-phase matrix 310. Therefore,in a first state, input line phases A, B, C are blocked from passingthrough the bi-phase matrix 310 when the respective switches are turnedoff.

However, if lower switch 315 is turned on, then input line C's voltagewill pass through switch 315 and also pass through switch 316, its diodebeing forward biased, to arrive at switch 312. If switch 312 is turnedon, then input line C's voltage and also input line A's voltage willpass, arriving at junction 317 of the bi-phase matrix 310. Also, ifswitch 311 is turned on, input line B's voltage will join the voltagesof input lines A and C at junction 317. As further progress is blockedby switch 313, when switch 313 is turned on, it allows the voltages toenter via junction 319 to DC source circuit 360 to charge power supply362.

In another mode of operation, if (upper) switch 313 is turned off, thepaths for input lines A, B, C can be altered by turning on/off variousbi-phase matrix 310 switches to allow the voltages to enter via (lower)switch 314 rather than (upper) switch 313. For example, input line A'svoltage can bypass around “blocked” switch 312 to enter turned on switch316 via the outer path to arrive at switch 314. Input line B can entervia turned on switch 311 and travel through the forward-biased diode ofswitch 312 to follow input line A's path and arrive at switch 314. Inputline C can enter through turned on switch 315 to arrive at switch 314.

In yet another mode of operation, both switches 313, 314 can operate tocoordinate entry into bi-phase matrix 310. For example, input lines Aand B may follow the paths described in the first example via switch 313while input line C may follow a path through directly through switch 315and 314. Of course, it is understood that in some switching circuits,the selection of path is dependent on the relative impedance of thetransistor as compared to the associated diode, and it may be necessaryto add additional switches to guarantee appropriate pathway selection.As one illustration, in the previous example, input line C, rather thantraveling from switch 315 directly to switch 314, may prefer to travelthrough the forward biased diode of switch 316. Accordingly, anotherswitch (or controllable diode or equivalent) could be devised betweenswitches 316 and 312 to prevent this travel path. As is evident, theembodiment of FIG. 3 lends itself to multiple modes of operation, whichcan be facilitated by operating the bi-phase matrix 310 switches in acoordinated manner. Therefore, one of ordinary skill in the art may makemodifications to the embodiments shown without departing from the spiritand scope of this disclosure.

Since input lines A, B, C of AC grid 110 are in phase relationship,operation of the various switches in the bi-phase matrix 310 can becoordinated to afford efficient superpositioning of the respectivevoltages and control of when/how much voltage will pass to DC sourcecircuit 360, by selection of the desired paths in view of the phaserelationships and/or line voltages. As one possible example, if one ofthe input line voltages is not of the same amplitude or phase relationas the remaining line voltages, a degree of compensation can be achievedby coordinating which line voltages will travel through whichpath/switches.

For situations where the line voltage is lower than normal or where it asituation requires the DC source circuit 360 to provide voltage additionto the system, power from power supply 362 is conveyed through thediodes associated with switches 313 and 314, to in-line switches of 311,312 and 315, 316, respectively. The final rectification phase is carriedout by the diodes associated with the rectifying input switches 120.

As is apparent, switching control of the rectifying input switches 120can be part of a traditional rectifier/inverter scheme to providesynchronous rectification, and may be operated by traditional spacevector modulation/control (SVM). Similarly, switching control of thebi-phase matrix 310 may be via SVM. The switching logic can be anautomated (e.g., computerized) system using decision logic (e.g.,software) for a desired mode of operation or performance. Feedbackand/or other system inputs may be utilized in such an embodiment. WhileSVM is articulated as one scheme for switch control, it is wellunderstood that other forms of switch control (traditional and/ornon-traditional) may be utilized and, therefore alternative switchingschemes and/or switch control may be utilized without departing from thespirit and scope of this disclosure. Recognizing the embodiment of FIG.3 as being capable of being bi-directional in operation, the switchcontrol topology can be responsible to carry out regenerative functions.By implementing a bi-phase matrix 310, the efficacy and robustness ofregeneration can be obtained through appropriate switch control.

With respect to switch behavior, synchronous zero voltage crossoverswitching can enhance the overall efficiency. Accordingly, for example,switches 313, 314 provide “bucking” energy back to the DC source circuit360 for energy replenishment in the case that the DC power source 362 iseither a battery, or ultracapacitor, for example.

FIG. 4 is a schematic diagram 400 of the embodiment of FIG. 3 modifiedwith a boost switching circuit 463. AC grid 110 is shown with shuntingelements 425, in conjunction with rectifying input switches 120 coupledto bi-phase switches 410. The bi-phase switches 410 are center fed byDC-source circuit 460 having assorted resistors 464, 466, capacitor 468,inductor 465, with power source 462, and also connected to boostswitching circuit 463. This additional circuit 463 was found tobeneficial, as a means for hosting the ability to control apre-determined increase in voltage at any time by changing the dutycycle of the circuit 463. While FIG. 4 illustrates a boost switchingcircuit 463 in a transistor-diode pair, additional circuit elements maybe added, according to design preference. As boosting circuits are wellknown, modifications within the purview of one of ordinary skill in theart may be made art without departing from the spirit and scope of thisembodiment. As one non-limiting example, the boost switching circuit 463may be of an alternative design/configuration, etc., having multiplestages, either in series and/or parallel.

FIG. 5 is a schematic diagram 500 of a multi-single phase and 3-phasesystem using a rectifier-based embodiment of FIG. 4's architecture. Thisembodiment contemplates a multiple “input” source paradigm where singlephase, 3-phase, and backup DC sources are “controllably” connected toprovide an integrated and robust power delivery system. The load-sideDC-to-AC rectifier/inverter and load is omitted in this diagram 500 forease of illustration, and in doing so presents an architecture that iscapable of connection to a multi-load and/or multi-DC-to-ACrectifier/inverter, as will be more apparent below.

In this embodiment, 3-phase AC grid 110 input lines feed into a simpleswitchless rectifier matrix 520 having shunt resistances/capacitances525. The rectifier matrix 520 is complemented by bi-phase matrix 510containing DC-source circuit 560 having shunt resistance 566, shuntcapacitance 568, DC-boost circuit 563, series inductance 565, shut-offswitch 564, series resistance 564 and DC power supply 562. Theseelements are similar in function to the corresponding elements describedin the embodiment of FIG. 4, in that backup or supplemental power can beobtained from DC power supply 562. As further evident below, it isrecognized for this embodiment that the mechanism for “charging” the DCpower supply 562 will naturally arise from the DC-bus 550 throughappropriate switch paths in the bi-phase matrix 510. However, in somevariations of this embodiment, it is contemplated that inverter module590 from 3-phase input 580 can be configured to operate as a chargingsource for DC power supply 562, as it can have the necessary set ofswitches to carry out the regenerative function, as in otherconfigurations. Therefore, modifications to this arrangement to arriveat additional functionalities are within the scope of one of ordinaryskill in the art.

The rectifier matrix 520 is complemented by secondary AC input linesource, which in this illustration is presented as 3-phase input 580,containing tap 582, line inductances 584, and inverter module 590,typically having 6 transistor-diode bridges (not shown). The invertermodule 590 is shown as a single element, but actually is a module thatcontains a controllable inverter architecture that can be bidirectionaland produces a DC output. Tap 582 provides a control signal 585 forcurrent and/or voltage (phase) information for coordinating control andsignaling 595 of inverter module 590. Control can be achieved by acomputer or logic chip (not shown) and may utilize SVM or otherapplicable modulation schemes for coordinating entry of the 3-phaseinput 580 voltage (now rectified) to DC-bus 550. The bi-directionalnature of inverter module 590 provides a mechanism for excess voltage onthe DC-bus 550 to be transferred to 3-phase input 580 for regenerativepurposes, if so needed.

Therefore, in addition to DC-bus 550 being coupled to rectified singlephase AC grid 110 voltage and, if desired, to DC power supply 562voltage, the DC-bus 550 is also be coupled to rectified 3-phase input580 voltage via connection bridge 577. Connection bridge 577 provides aconvenient mechanism for “joining” the rectified outputs of AC gird 110and 3-phase input 580. Wherein DC-bus 550 provides an output channel toan AC-producing inverter (not shown) or respective load (not shown). Itis understood that connection bridge 577 may contain a switch forconnection or disconnection, depending on implementation preference.

As is apparent, for some embodiments the nature of deployment may besuch that the load is a DC load and therefore an interveningAC-producing inverter may not be necessary. Therefore, via the variouscontrollable connections provided in this embodiment, combinations ofthe single phase AC grid 110, 3-phase input 580, DC power supply 562 canbe devised for supporting a desired load(s) or load type.

It should be noted that the above embodiment can be understood asproviding a dual path formed from a separate rectifier matrix 520,bi-phase matrix 510, and inverter module 590, to perform the function ofthree phase rectification from separate three phase AC input sources.The outputs of these two rectifier architectures are combined at theDC-bus 550 to enhance power quality, efficiency and regenerativecapability. Since the rectifier architecture 520 supporting the bi-phasematrix 510 can be uni-directional, it can be responsible for creating ahigher quality DC-bus 550 voltage for instances where step loads occur.Concomitantly, the rectifier architecture 590 supporting the 3-phaseinput 580 is bi-directional and therefore enables the commuting ofregenerative energy back to the 3-phase input 580.

It is understood that some circuit elements shown in the aboveembodiments may be superficial or replaced with an equivalent circuit(series vs. parallel, for example) or added to, and therefore whilevarious series/shunt inductors, capacitors, and resistors (as well asdiodes) are illustrated in the particular configuration shown, alternateconfigurations, as well as additions or subtractions, may becontemplated by one of ordinary skill in the art, without departing fromthe spirit and scope of this disclosure.

For example, some resistances, capacitances (and also inductances, ifapplicable) may be, in some embodiments, considered intrinsic circuitequivalences, which may be considered negligible or ignored, dependingon the sophistication of simulation being performed. Accordingly,depending on the “accuracy” desired, these intrinsic equivalences may beremoved and the modified architecture may suitably operate.

While FIG. 5 illustrates various switches in a transistor-diode pair,additional or different circuit elements may be added, according todesign preference, for example, having multiple stages, multiple diodes,and so forth. Also, on/off terminology is dependent on the mode anddefault state of a transistor/switch, therefore, the term “on” may implyturning “off” the voltage/current to the transistor (or switch) to allowpassage. Further, while “voltage” is described as the power parameter,current may be used as the power parameter, as appropriate.

By way of illustration from FIG. 5, the embodiments of FIGS. 3 and 4 canbe modified by incorporating a connecting bridge that connects a second3-phase AC line input source to the representative DC-bus. Pursuing thisapproach, it can further be seen that while two rectifier/inverterarchitectures can be implemented in the embodiment of FIG. 5 and also byextension to the embodiments of FIGS. 3-4, three or morerectifier/inverter architectures can be implemented by appropriatebridging. The bridging aspect enables not only support for a pluralityof rectifier/inverters, it is capable of supporting a plurality of loads(via bridging directly to the plurality of loads), as is furtherexplored below in the descriptions of the embodiments of FIGS. 15A-F.

FIG. 6 is a block diagram 600 of a modified inverter system undercontroller operation. A computing device 610 provides control signals toinverter system 630 via communication link 615. Communication link 615can be a one-way or two-way signal, depending on implementationpreference. Computing device 610 can be part of a network, bycommunicating to a server of the server system 620 via communicationslink 605, depending on implementation preference. Server system 620 canalso provide control signals to inverter system 630 via communicationslink 625. Communication link 625 can be a one-way or two-way signal,depending on implementation preference. Also, computing device 610 mayoperate independent of server system 620 or operate in coordination withserver system 620. In some embodiments, computing device 610 may be partof inverter system 630 and constitute a stand-alone system, with no oronly as needed communication to exterior computers such as server system620.

Control signals sent via communications links 615, 625 provide switchingsignals for various switches (transistor and/or non-transistor basedswitches, etc.) within inverter system 630. For example, elements 645within inverter system 630 may be a connection bridge between threephase power input 640 to single phase power input 650. And element 655within inverter system 630 may be a connection bridge between DC powersource or circuit 660 to single phase power input 650. In someembodiments, three phase power input 640 may be removed, leaving onlysingle phase power input 650 and DC power source/circuit 660. Similarly,DC power source/circuit 660 may be removed, leaving only three phasepower input 640 and single phase power input 650. Other combinations maybe contemplated. Connection bridges 645, 655 can be controllableswitches that are controlled via control signals from links 615, 625, ormay be hard-connections without any ability for control, depending onimplementation preference.

Communications links 615, 625 can also provide feedback, tap informationfrom the switches or from other parts of the inverter system 630.Feedback to computing device 610 and/or server system 620 can also arisefrom communication links 685, 695, which can come from load 680, whichis connected to inverter system 630 via DC-bus 670. One or more of thecommunication links 605, 615, 625, 685, 694 may be wireless, dependingon design preference. Communication links 685, 695, though shown as onlyhaving one-way communications, may have two way or one-way in thereverse direction, according to design preference. For example, directcontrol of a cutoff switch (not shown) at the load 680 may be affordedthrough control signals sent from computing device 610 and/or serversystem 620 to load 680.

FIG. 6's block diagram 600 is offered to illustrate one of many possiblecommunication pathways between controller(s) (e.g., computer orprocessor) and various functional blocks in bi-phase matrix modifiedinverter systems. It is understood that such controller(s) will utilizesoftware-based commands and logic to provide the appropriate control andswitching of various connections and/or switches in bi-phase matrixmodified inverter systems. And based on the configuration chosen andperformance objectives desired, it is understood that using the templateoffered in FIG. 6, various modifications to the connections andlogic/switching decisions may be made by one of ordinary skill in theart without departing from the spirit and scope of this disclosure. Asone possible hardware based example, computing device 610 maycommunicate with a processor (not shown) interior to inverter system630, being “integrated” therein and the processor may provide thelogic/switching decisions. As one possible software based example, oneswitching scheme for a set of switches may be SVM based while anotherswitching scheme (non-SVM) for another set of switches.

FIG. 7 is a flow process 700 illustrating event-based control of abi-phase matrix with DC-power circuit supplemented inverter/rectifyingsystem, upon detection of a “problem” event that requires power systemadjustment. For ease of description, the events are categorized into twosets, corresponding to DC-Bus instability 710 and Regenerative EnergyRouting 780, however, they may be separated into smaller sets, dependingon implementation preference. The process 700 will start 705 withmonitoring a status of the power system, to detect of any one or more ofthese disturbance “events.” Detection of a DC-Bus Instability event 710,typically arising from an AC-Grid power fluctuation (e.g., brown out) orLoad Torque perturbation (e.g., start/stop/heavy load), etc., willtrigger the process 700 to inquire if the DC Power Source is available715 for use as a power source to supplement the power to the load. Ifthe DC power source is understood to be available, the process 700 willactivate the regenerative cell operation 720, which “kicks in” the DCpower source as a supplemental or replacement power source by applyingstep-voltage for “ride-through” the DC-Bus link from the DC power source730.

It is understood, in the context of this flow process 700, that the termregenerative cell operation denotes operation of the power system usingone or more of its secondary power systems (for example, DC powersupply, 3-phase power, and so forth). Upon the activation or completionof the ride through 730, the process 700 can stop 745 or loop back toStart 701 for further event monitoring.

If, in Step 715, the DC power source is understood to not be available,the process 700 will proceed to inquire if non-availability is due tothe DC power source having a low voltage condition 725. If low voltagecondition 725 is found to be true, the process 700 will proceed toinvoke a charging operation by transferring available regenerativeenergy to the DC power source 735, whereupon upon completion the process700 can stop 745 or loop back to Start 705 for further event monitoring.This flow path, of course, presumes that regenerative energy isavailable.

If low voltage condition 725 is found not to be true, then the process700 will proceed to inquire if the DC power source requires charging750. If the DC power source requires charging 750, the process 700 willproceed to step 735—transferring (if) available regenerative energy tothe DC power source. Upon the activation or completion of this function,the process 700 can stop 745 or loop back to Start 705 for further eventmonitoring.

At step 750, if the DC power source does not require charging, theprocess 700 proceeds to activate the regenerative cell operation 755,which in this instance involves setting the appropriate switches for anyregenerative energy to be transferred to the AC Grid 765 (for example,for rebate purposes, etc.). After activation or completion of thisfunction, the process 700 can stop 745 or loop back to Start 705 forfurther event monitoring.

For the scenario where the triggering event is in regards toRegenerative Energy Routing 780, beginning with Start 705, the process700 will monitor excess voltage from the Output Load Source or DC-PowerSource, etc. Detection of over-voltage will trigger the process 700 toinquire if the DC Bus Voltage is genuinely greater than the InputVoltage 770 and not the result of a transient voltage. If the DC BusVoltage is actually determined to be less than the Input Voltage, thenthe process 700 will ignore this event trigger and return to Start 705for further event monitoring. However, if the DC Bus Voltage is found tobe greater than the Input Voltage 770, then the process 700 will proceedto inquire if the DC power source requires charging 750. If the DC powersource requires charging 750, then the process 700 will proceed toinvoke a charging operation by transferring available regenerativeenergy to the DC power source 735, whereupon upon completion the process700 can stop 745 or loop back to Start 705 for further event monitoring.

At step 750, if the DC power source does not require charging, theprocess 700 proceeds to activate the regenerative cell operation 755,which in this instance involves setting the appropriate switches for anyregenerative energy to be transferred to the AC Grid 765. Afteractivation or completion of this function, the process 700 can stop 745or loop back to Start 705 for further event monitoring.

The following FIGS. are computer simulations of a related art invertersystem compared to modified inverter embodiments described above, indifferent modes of operation, showing performance improvements over therelated art. DC Bus voltages, input phase currents, DC link current,Motor stator currents, and Positive & Negative load steps as a functionof time (seconds) are plotted for comparison purposes.

FIG. 8 is a plot 800 of a computer simulation of the related artembodiment of FIG. 1. No bi-phase matrix or DC power source is utilized.This embodiment operates as a traditional 6-switch bridge rectifiersystem. The effects of a motor load shifting from positive to negative100 N·m (810) at the motor shaft are seen in the DC-Bus voltage andDC-Bus link current plots. The DC-Bus voltage was calculated to have aminimum of 300V and a maximum of 430 through the load shift. The RMSvalue was computed as 375V. The distortion of the Input Phase Currentsis attributed to the low voltage response of the rectifier system.

FIG. 9 is a plot 900 of a computer simulation of a modified invertersystem corresponding to the embodiment of FIG. 4 whereby a DC voltage of200V is added to the intersection of switch 413 (FETD3) and switch 414(FETD4). This action simulates the transmuting of the DC power source's460 output voltage (e.g., 200 VDC) to the DC-Bus 450, in a regenerativemode where the DC power source is used to supplement the input AC Grid110 power. The effects of a motor load shifting from positive tonegative 100 N·m (910) at the motor shaft are seen in the DC-Bus voltageand DC-Bus link current plots. The minimum value of the DC-Bus voltagewas computed to be 534V while the maximum value of the DC-Bus voltagewas 608V, through the load shift, giving an RMS value of 567V. Asignificant improvement in the general system response is evident overthe related art embodiment of FIG. 1. A near 200V RMS increase in theDC-Bus voltage is evident. The insertion of a positive DC-offset voltagevia the bi-phase matrix 410 configuration enhances the power quality ofthe input currents and reduces the distortion when positive, ornegative, step loads are applied.

FIG. 10 is a plot 1000 of a computer simulation of the embodiment ofFIG. 4 whereby a DC voltage of 200V is added to the intersection ofswitch 413 (FETD3) and switch 414 (FETD4) and boost switching circuit463 is engaged. This simulates the transmuting of the DC power source's460 output voltage (e.g., 200 VDC) to the DC-Bus 450 with the boostswitching circuit's 463 contribution, in a regenerative mode where theboosted DC power source is used to supplement the input AC Grid 110power. The effects of a motor load shifting from positive to negative100 N·m (1010) at the motor shaft are seen in the DC-Bus voltage andDC-Bus link current plots. The minimum value of the DC-Bus voltage is688V while the maximum value of the DC-Bus voltage is 770V, through theload shift, giving an RMS value of 730V. This RMS value is nearly 170Vhigher than that experienced in the simulation of FIG. 9.

From this plot 1000, the “simple” boost switching circuit 463 appears tobe very effective in increasing the voltage to the load when under heavydemand. The bi-phase matrix 410 enables the voltage from the boosted 463DC power source 460 to provide a voltage that can be used to eitherincrease the robustness of the DC-link against output load changes, orprovide compensation for grid brown-out events, for example. Varioussimulation results have demonstrated that by controlling the duty cycleof the boost switching circuit 463, the delta between the minimum tomaximum DC-link voltage swing can be maintained to within 5% of targetvalues, throughout load excursions.

As stated above, feedback mechanisms can be used to further refine thecontrol aspects described herein. The boosting of the DC power source460 can be controlled to occur on an as-needed basis, for example, whenexperiencing heavy load perturbations, or for other disturbances. The“amount” of boost can also be controlled. Therefore, this embodiment ismore efficient allowing for various as-needed responses.

FIG. 11 is a plot 1100 of a computer simulation of the embodiment ofFIG. 4 whereby the DC power source 460 is not “connected” to thebi-phase matrix 410, due to switches 413 (FETD3) and 414 (FETD4) beingin a switched mode to block the contribution of voltage from the DCpower source 460. Of course, this can also be accomplished by openingswitch 469. Nonetheless, in a non-DC power source supplemented mode, theDC-Bus voltage has a minimum of 408V and a maximum of 496V during thepositive to negative 100 N·m torque change 1110 at the motor shaft. TheRMS voltage was calculated to be 450V. While the bi-phase matrix 410 isconsidered to be in operation, the lack of contribution from the DCpower source 460 is evident in the reduced DC-Bus voltage. Evident inthis plot is the higher harmonic content of the DC link voltage,resulting from the absence of the DC power source's 460 contribution.

The summary from the above plots is that integration of a bi-phasematrix with a DC power source into a conventional rectifier/inverterpower system will significantly enhance the stability, efficiency, andpower quality of three-phase AC regenerative rectification systems.

FIG. 12 is a plot 1200 of a computer simulation of the embodiment ofFIG. 5, without the DC link 577 link between rectifier inverter module590 and rectifier matrix 520. The plot of the DC V voltage representsthe DC-bus 550 voltage from the rectifier inverter module 590 (coupledto 3-phase input 580) to a load, with no connection to bi-phase matrix510. The plot of the Bi-Phase Matrix voltage represents the DC-bus 550voltage from the bi-phase matrix 510 to a load. These plots show theresponse of the respective rectifier systems operating independentlyfrom each other.

For a 100 N·m torque change 1210 at the motor shaft, the ensuing DC Vvoltage was calculated to have a minimum of 317V and maximum of 405V,with an RMS voltage of 365V. The corresponding Bi-Phase Matrix voltagewas calculated to have a minimum of 635V and maximum of 646V, with anRMS voltage of 643V. No energy was provided by DC power source 560 forthe Bi-Phase Matrix simulation.

FIG. 13 is a plot 1300 of a computer simulation of the embodiment ofFIG. 5 whereby there is a common link between rectifier inverter module590 and rectifier matrix 520. That is, both rectifier systems aresimultaneously connected to the DC-bus 550. However, there is nocontribution from the DC power source 560. The DC V voltage and theBi-Phase Matrix voltages are identical, as should be expected and wascalculated to have a minimum of 418V and maximum of 430V through the 100N·m torque change 1310 at the motor shaft. The RMS voltage wascalculated as 424V. It is believed that the current limiters areclamping the voltage swing with a small delta voltage. The Input PhaseCurrents plot is significantly more symmetrical than those seen in FIG.12.

FIG. 14 is a plot 1400 of a computer simulation of the embodiment ofFIG. 5 with a common link between rectifier inverter module 590 andrectifier matrix 520, and also contribution from the DC power supply560, including the DC-boost circuit 563. As expected, the DC V voltageand the Bi-Phase Matrix voltages are identical, however, they show aboosted minimum of 570V and boosted maximum of 609V through the 100 N·mtorque change 1410 at the motor shaft. The RMS voltage was calculated as579V. The addition of the DC power supply 560 with DC-boost circuit 563can be seen to provide a significant improvement.

The contribution from the boost circuit 563 (e.g., output of DC powersupply 560) can be controlled to adjust the amount of DC voltagecontribution to the DC-bus 550. The ability to adjust the DC-bus 550voltage allows loads such as electric motors to operate at an optimalefficiency without concern for input source matching capability. Theflexibility of the boost circuit 563 can be seen by having one boostcircuit 563 serving the needs of either a single motor, or a dual systemwith two output loads. Additionally, the independence of the bi-phasematrix 510 allows for opportunities to boost additional regenerativeenergy back to the bi-directional rectifier inverter module 590, foradditional power recovery.

FIG. 15A is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system 1500 with a singleinput, single output. A single AC line input source 1502 feeds themodified inverter system 1500 and the system outputs “controlled” ACthree phase power 1508, for use by a load (not shown). Thebi-directional arrows of the single AC line input source 1502 convey thefact that bi-directional flow of power can occur (i.e., regeneration ofpower “into” the AC line input source 1502 from the modified invertersystem 1500). The modified inverter system 1500 comprises the inputrectifier/inverter 1504 (labeled in these and the following FIGS. as SVMto simply distinguish from the bi-phase matrix) and bi-phase matrix1506, as described in the above embodiments. Input rectifier/inverter1504 is shown as “overlapping” bi-phase matrix 1506 to signify that theyjointly form a single inverter architecture that supplies DC power to DCbus link 1505. The output of DC bus link 1505 is coupled to a singleDC-AC inverter 1507, which generates a single controlled AC three power1508. This block diagram serves as “shorthand” for the top levelconnections found in the embodiment of FIG. 3.

FIG. 15B is a simplified block diagram approach for illustrating toplevel connections for another modified inverter system 1510 with dualinput, bridging and single output. Two AC line input sources 1512 (forexample, AC line power and AC generator power) fed the modified invertersystem 1510 and the system outputs “controlled” AC three phase power1518, for use by a load (not shown). The bi-directional arrows of thedual AC line input sources 1512 convey the fact that bi-directional flowof power can occur. The modified inverter system 1510 comprises the(SVM) input rectifier/inverter 1514 and bi-phase matrix 1516, asdescribed in the above embodiments. SVM inverter 1514 does not overlapwith bi-phase matrix 1516, but is shown as being separate. However,mutual connection to DC-bus link 1515 is facilitated by connectingbridge(s) 1513. Power from the DC-bus link 1515 is converted to AC viasingle DC-AC inverter 1517 to AC three phase power for subsequentpowering of a load (not shown).

FIG. 15C is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system 1520 with a singleinput, a DC power supply, and single output. The modified invertersystem 1520 is fed by a single AC line input source 1522 to output asingle AC three phase load power 1528. The bi-directional arrows of thesingle AC line input source 1522 convey the fact that bi-directionalflow of power can occur. The modified inverter system 1520 comprises(SVM) input rectifier/inverter 1524 and bi-phase matrix 1526, asdescribed in the above embodiments. SVM rectifier/inverter 1524 is shownas “overlapping” bi-phase matrix 1526 to signify that they jointly forma single inverter architecture that supplies DC power to DC bus link1505. Additionally, DC power source 1529 (with or without boosting) iscoupled to the bi-phase matrix 1526 as an extra energy port, as detailedin the above embodiments. The “co-joined” inverter architecture providesa DC output which is channeled by DC bus link 1525 a single DC-ACinverter 1527, which outputs a single AC three phase power 1528 to aload (not shown). This block diagram serves as “shorthand” for the toplevel connections found in the embodiment of FIG. 4.

FIG. 15D is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system 1530 with dual input,bridging and dual outputs. Two AC line input sources 1532 (for example,AC line power and AC generator power) fed the modified inverter system1530 and the system outputs two “controlled” AC three phase power 1538,for use by a load(s) (not shown). The bi-directional arrows of the dualAC line input sources 1532 convey the fact that bi-directional flow ofpower can occur. The modified inverter system 1530 comprises an (SVM)input rectifier/inverter 1534 and bi-phase matrix 1536, as described inthe above embodiments. SVM inverter 1534 does not overlap with bi-phasematrix 1536, but is shown as being separate. However, connection to twoDC-bus links 1515 is facilitated by connecting bridge(s) 1513. EachDC-bus link 1515 is coupled to a separate DC-AC inverter (1537 a, 1537b), which converts the supplied DC power to AC three phase power 1538.Since the DC-AC inverters (1537 a, 1537 b) are separate, the output ofthe modified inverter system 1530 can also be separate, providing powerfor two loads, if so desired. Of course, switching of paths (todifferent DC-AC inverters) may be implemented according to designpreference.

FIG. 15E is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system 1540 with dual input,bridging, DC power supply and single output. Two AC line input sources1542 (for example, AC line power and AC generator power) fed themodified inverter system 1540 and the system outputs “controlled” ACthree phase power 1548, for use by a load(s) (not shown). Thebi-directional arrows of the dual AC line input sources 1542 convey thefact that bi-directional flow of power can occur. The modified invertersystem 1540 comprises an (SVM) input rectifier/inverter 1544 andbi-phase matrix 1546, as described in the above embodiments.Additionally, DC power source 1549 (with or without boosting) is coupledto the bi-phase matrix 1546 as an extra energy port, as detailed in theabove embodiments. SVM inverter 1544 does not overlap with bi-phasematrix 1546, but is shown as being separate. Connection to a DC-bus link1545 is facilitated by connecting bridge 1543. DC power from the DC-buslink 1545 is converted to AC via a single DC-AC inverter 1547, whichoutputs a single AC three phase power 1528 to a load (not shown). Thisblock diagram serves as “shorthand” for the top level connections foundin the embodiment of FIG. 5.

FIG. 15F is a simplified block diagram approach for illustrating toplevel connections for a modified inverter system 1550 with dual input,bridging, DC power supply, and dual outputs. Two AC line input sources1552 (for example, AC line power and AC generator power) fed themodified inverter system 1550 and the system outputs two “controlled” ACthree phase power 1558, for use by a load(s) (not shown). Thebi-directional arrows of the dual AC line input sources 1552 convey thefact that bi-directional flow of power can occur. The modified invertersystem 1550 comprises an (SVM) input rectifier/inverter 1554 andbi-phase matrix 1556, as described in the above embodiments.Additionally, DC power source 1559 (with or without boosting) is coupledto the bi-phase matrix 1556 as an extra energy port, as detailed in theabove embodiments. SVM inverter 1554 does not overlap with bi-phasematrix 1556, but is shown as being separate. However, connection to twoDC-bus links 1555 is facilitated by connecting bridge(s) 1553. EachDC-bus link 1555 is coupled to a separate DC-AC inverter (1557 a, 1557b), which converts the supplied DC power to AC three phase power 1558.Since the DC-AC inverters (1557 a, 1557 b) are separate, the output ofthe modified inverter system 1550 can also be separate, providing powerfor two loads, if so desired. Of course, switching of paths (todifferent DC-AC inverters) may be implemented according to designpreference.

It is apparent that given the various iterations and numerouscombinations shown in the above embodiments, additional modificationsand changes within the purview of one ordinary skill in the art may bemade without departing from the spirit and scope of this disclosure.

It was noted above that a system controller may be integrated into theoverall system or separate, being a computer or processing device whichmay be under automatic software operation. Accordingly, some embodimentsof the present disclosure, or portions thereof, may combine one or morehardware components such as microprocessors, microcontrollers, ordigital sequential logic, etc., such as processor with one or moresoftware components (e.g., program code, firmware, resident software,micro-code, etc.) that is stored in a non-transitory form in a tangiblecomputer-readable memory device such as semiconductor memory,magnetically stored memory, optically stored memory, and other now orfuture devised memory devices to support computing operations. Forexample, a software application using volatile or non-volatile memory ina hardware machine could be utilized to achieve the desired functions.Also, hardware objects could communicate using electrical signals, withstates of the signals representing different data which are interpretedby the software components for appropriate controlling of switches, etc.

These hardware-software combinations can form specially-programmeddevices which may be generally referred to herein as “modules”. Thesoftware component portions of the modules may be written in anycomputer language and may be a portion of a monolithic code base, or maybe developed in more discrete code portions such as is typical inobject-oriented computer languages. In addition, the modules may bedistributed across a plurality of computer platforms, servers,terminals, and the like.

It should be further understood that this and other arrangementsdescribed herein are for purposes of example only. As such, thoseskilled in the art will appreciate that other arrangements and otherelements (e.g. machines, interfaces, functions, orders, and groupings offunctions, etc.) can be used instead, and some elements may be omittedaltogether according to the desired results. Further, many of theelements that are described are functional entities that may beimplemented as discrete or distributed components or in conjunction withother components, in any suitable combination and location.

Further, although process steps, logic, flow, algorithms or the like aretypically represented as software instructions described in a sequentialorder, such processes may be configured to work in different orders. Inother words, any sequence or order of steps that may be explicitlydescribed does not necessarily indicate a requirement that the steps beperformed in that order. The steps of processes described herein may beperformed in any order practical. Further, some steps may be performedsimultaneously despite being described or implied as occurringnon-simultaneously (e.g., because one step is described after the otherstep). Moreover, the illustration of a process by its depiction in adrawing does not imply that the illustrated process is exclusive ofother variations and modifications thereto, does not imply that theillustrated process or any of its steps are necessary to the invention,and does not imply that the illustrated process is preferred.

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its scope, as will be apparent to thoseskilled in the art. Functionally equivalent methods and apparatuseswithin the scope of the disclosure, in addition to those enumeratedherein, will be apparent to those skilled in the art from the foregoingdescriptions. Such modifications and variations are intended to fallwithin the scope of the appended claims. The present disclosure is to belimited only by the terms of the appended claims, along with the fullscope of equivalents to which such claims are entitled. It is to beunderstood that this disclosure is not limited to particular methods,implementations, and realizations, which can, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those skilled in the art that, in general,terms used herein, and especially in the appended claims (e.g., bodiesof the appended claims) are generally intended as “open” terms (e.g.,the term “including” should be interpreted as “including but not limitedto,” the term “having” should be interpreted as “having at least,” theterm “includes” should be interpreted as “includes but is not limitedto,” etc.). It will be further understood by those within the art thatif a specific number of an introduced claim recitation is intended, suchan intent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A multi-mode, regenerative AC-DC-AC inverterpower system, comprising: a first inverter bridge with controllableswitches configurable for coupling to line inputs from a 3-phase ACpower source; a bi-phase matrix (BP-Mtx) containing reverse currentoriented, series-connected sets of controllable BP-Mtx switches, whereininputs to a first and second set of controllable BP-Mtx switches arecoupled to the inputs of the first inverter bridge, and outputs of thefirst and second set of controllable BP-Mtx switches are coupled toinputs to a third set of controllable BP switches; a chargeable DC powersupply coupled to an output of the third set of controllable BP-Mtxswitches; a DC-bus coupled to outputs of the first inverter bridge; anda second inverter bridge with controllable switches, inputs thereofcoupled to an opposite end of the DC-bus from the first inverter bridge,and outputs thereof configurable for coupling to a load, whereinswitches of at least the first inverter bridge, second inverter bridge,and BP-Mtx are controllable to charge the DC power supply from at leastone of excess voltage from the line inputs and DC-bus, and to providecompensating energy from the DC power supply for load or line inputperturbations.
 2. The system of claim 1, wherein the DC bus is shuntedby at least a DC voltage stabilizing capacitor.
 3. The system of claim1, wherein the DC power supply comprises at least one of a battery, anultracapacitor, and disconnect switch.
 4. The system of claim 1, furthercomprising a switch controller, controlling switches of at least thefirst inverter bridge, second inverter bridge, and BP-Mtx.
 5. The systemof claim 4, wherein the switch controller utilizes a State Vector Method(SVM) for switch modulation.
 6. The system of claim 1, wherein switchesof at least the first inverter bridge, second inverter bridge, andBP-Mtx are at least one of diode bridged, field-effect transistors(FETs), power metal-oxide-semiconductor-effect transistors (MOSFETs),and insulated-gate-bipolar Transistors (IGBT).
 7. The system of claim 1,wherein the first inverter bridge and second inverter bridge are of asimilar arrangement of six diode-bridged transistors in forward currentoriented pairs connected in parallel, and the BP-Mtx switches are sixdiode-bridged transistors in an arrangement of non-parallel-connectedupper switch pair, lower switch pair, and middle switch pair, wherein afirst input of the middle switch pair is coupled to an output of theupper switch pair and a second input of the middle switch pair iscoupled to an output of the lower switch pair.
 8. The system of claim 1,further comprising: line inputs from a 3-phase AC power source coupledto the first inverter bridge; and a load coupled to the second inverterbridge.
 9. The system of claim 1, further comprising a DC boost circuitcoupled to the DC power supply.
 10. A multi-mode, regenerative AC-DC-ACinverter power system, comprising: a rectifying bridge configurable forcoupling to line inputs from a first 3-phase AC power source; a bi-phasematrix (BP-Mtx) comprising, reverse current oriented, series-connectedsets of controllable BP-Mtx switches, wherein inputs to a first andsecond set of controllable BP-Mtx switches are coupled to inputs of therectifying bridge, and outputs of the first and second set ofcontrollable BP-Mtx switches are coupled to inputs to a third set ofcontrollable BP-Mtx switches; a chargeable DC power supply coupled to anoutput of the third set of controllable BP-Mtx switches; a bridgeconnection coupled to outputs of the rectifying bridge and to a DC-busconfigurable for coupling to a load; and an inverter bridge withcontrollable switches, configurable for coupling to line inputs from asecond 3-phase AC power source, wherein an output of the inverter bridgeis coupled to at least one of the bridge connection and the DC-bus,wherein switches of at least the BP-Mtx and inverter bridge arecontrollable to charge the DC power supply from at least one of excessvoltage from the line inputs and DC-bus, and to provide compensatingenergy from the DC power supply for load or line input perturbations.11. The system of claim 10, wherein the DC-bus is shunted by at least aDC voltage stabilizing capacitor.
 12. The system of claim 10, whereinthe DC power supply comprises at least one of a battery, anultracapacitor, and disconnect switch.
 13. The system of claim 10,further comprising a switch controller, controlling switches of at leastthe BP-Mtx and inverter bridge.
 14. The system of claim 13, wherein theswitch controller utilizes a State Vector Method (SVM) for switchmodulation.
 15. The system of claim 10, further comprising a DC boostcircuit coupled to the DC power supply.
 16. The system of claim 10,wherein switches of at least the BP-Mtx and inverter bridge are at leastone of diode bridged, field-effect transistors (FETs), powermetal-oxide-semiconductor-effect transistors (MOSFETs), andinsulated-gate-bipolar Transistors (IGBT).
 17. The system of claim 10,wherein the BP-Mtx switches are six diode-bridged transistors in anarrangement of non-parallel-connected upper switch pair, lower switchpair, and middle switch pair, wherein a first input of the middle switchpair is coupled to an output of the upper switch pair and a second inputof the middle switch pair is coupled to an output of the lower switchpair.
 18. A method of operating a multi-mode, regenerative AC-DC-ACinverter power system, comprising: a computerized system controllerdetecting a bus instability event in a multi-mode, regenerative AC-DC-ACinverter power system, and upon detection; and automatically determiningif a de power source coupled to the system is available for powerregeneration and if so, automatically activating a regeneration mode andapplying voltage from the dc power source to the system; wherein if thedc power source is not available for power regeneration, automaticallydetermining if the dc power source has a low voltage and if so,automatically charging the dc power source from available power, whereinif the dc power source does not have low voltage, automaticallydetermining if the dc power source is charging and if so, automaticallycharging the dc power source from available power, wherein if the dcpower source is not charging to automatically activate the regenerationmode and apply voltage from the dc power source to the system.
 19. Themethod of claim 18, further comprising, after completion of at least oneof the steps of applying voltage from the dc power source to the systemand charging the dc power source from available power, automaticallyreturning to detecting a bus instability event.
 20. The method of claim19, further comprising, upon activating a regeneration mode,determining, by the controller, if a voltage of a dc bus of the systemhas a voltage greater than a voltage of an AC grid input and if so,proceeding to the step of automatically determining if the dc powersource is charging, wherein if the voltage of the dc bus is less thanthe voltage of the AC grid input, returning to a regeneration modemonitoring mode.